In early 2026, the world lost Barry Bloom, a great advocate for public health, an extraordinarily accomplished immunologist, and a science advisor who helped refocus policy on controlling infectious diseases, including neglected diseases such as leprosy. Barry's career took him from a life of laboratory discovery where he was enormously influential in catalyzing the late 20th century shift from studying the immune response of simple molecules to pathogenic microbes. As Dean of Harvard T.H. Chan School of Public Health he had a profound influence on the growth of the institution and the careers of many who have continued his work.